Two known printing methods are thermal transfer printing and dye sublimation printing. These two printing methods are based on the basic principle that a carrier film coated with coloring matter is guided onto the medium to be printed and heated by means of a thermal print head. This thermal print head has a multiplicity of heating elements which can be individually heated and constitute individual image points—that is to say pixels—for this printing method. A heated heating element causes the coloring matter at the appropriate point on the carrier film to detach and to be absorbed by the medium to be printed—referred to as substrate—where, in turn, it solidifies. In other words, in such a printing operation, ink particles are released sectionally from the ink ribbon and transferred to the object to be printed.
In thermal transfer printing, the detachment of the coloring matter is effected in that the coloring matter is melted, whereas, in dye sublimation printing, the coloring matter is converted to a gaseous state. Controlled heating of the heating elements and detachment of the coloring matter from the carrier film enables any pattern or image to be produced on the medium to be printed.
A further known method provides that a carrier film coated with coloring matter—as described—is in turn guided onto the medium to be printed, however this time heated by means of a stamp-like printing plate, on which printing plate a contour corresponding to the required print image is permanently structured. Although, in this case, the whole stamp is heated, it only comes into contact with the carrier film at the contoured points, as a result of which ink particles are only transferred from the ink ribbon to the medium to be printed at these points. This method is also referred to as the hot embossing method and, with regard to its ink transfer mechanism, corresponds to thermal transfer printing and dye sublimation printing with the difference that the contour to be printed is permanently defined by the form of the stamp.